This invention relates to positioning systems in resistance welding machines. During the welding process a consumable component, known as a welding electrode, must be maintained in the proper position to ensure a proper weld. Misalignment of the electrode occurs due to electro-mechanical erosion.
In resistance welding machines, the product components to be welded are clamped in proper relationship to one another and welded together maintaining the desired form. Two welding electrodes are used during the welding process, one on each surface of the product components. One electrode has a variable position to provide clearance for insertion and removal of the product components being welded. The other electrode maintains a stationary position.
The stationary electrode must maintain the proper position to mechanically resist the welding force and conduct the high welding currents. As welding occurs, the stationary electrode deteriorates and must be adjusted to maintain proper welding position.
In the state-of-art resistance welding machines, adjustment of the stationary electrode is made by unclamping the electrode, turning a bolt in communication with the electrode thereby adjusting it to proper welding position, then re-clamping the electrode in place.
Precise adjustment is difficult to achieve in most cases because adjustment devices cannot be reached with the product components clamped in place. Proper location of the stationary electrode resting against the surface of the product components is in question if the product components are not in place when the adjustment is made. When the variable electrode and stationary electrode are not pressing tightly against the product components, as proper adjustment would achieve, the welding forces which are calculated to create a quality weld are consumed by deforming the clamped product until it contacts the stationary electrode. This prevents a quality weld from being constructed at the prescribed schedule of current, time and force for which the machine was designed.